Air mattress



FIG. 1 is a top plan view of an air mattress showing my new design, the bottom being a mirror image of that shown, and the pattern of elements being understood to repeat uniformly across the surface represented;

FIG. 2 is an end elevational view thereof, the opposite end being a mirror image of that shown;

FIG. 3 is a side elevational view thereof, the opposite side being a mirror image of that shown; and,

FIG. 4 is an enlarged fragmentary top plan view of one corner thereof, the pattern of elements being understood to repeat uniformly across the surface represented. 

The ornamental design for an air mattress, as shown and described. 